Agricultural Research Service Research Articles

National dairy research programs: what is their role in animal health and sustainability research?

The US dairy industry has made great strides in improving animal health over many decades, which has driven substantial improvements in economic, social, and environmental sustainability. As consumer and corporate focus on climate continues to grow, the continued need to research and improve animal health and understand its connection with the environment is integral to the success of the dairy industry. Research to address these areas can be supported by national research programs and collaboration between them. The USDA and Dairy Management Inc established a collaborative research agreement in 2007; to date, this collaboration has not explicitly focused on animal health or its intersection with the environment. It is integral to the success of animal agriculture in an ever-changing sustainability landscape that animal health is addressed as a key piece of socioeconomic and environmental sustainability. An academic-industry stakeholder committee reached a consensus that supported this idea and identified that it is equally important to communicate these research findings with consumers in a way that resonates. The purpose of this Viewpoint article is to highlight that national research programs at the USDA Agricultural Research Service's National Animal Disease Center and Dairy Management Inc can and should play an important role in supporting and facilitating research at the intersection of animal health and sustainability broadly.

Southern blight of water lily: The first host record of Agroathelia rolfsii on Nelumbo nucifera discovered in Florida, USA.

Nelumbo nucifera Gaertn. (Nelumbonaceae, Eudicots), also known as water lily or sacred lotus, is a nonnative and invasive plant commonly found in artificial ponds and natural lakes throughout Florida (UF-IFAS 2023; Wunderlin et al. 2023). In August 2020, a single sample of water lily plants showing large leaf spots were collected at a residence in Dunnellon, Marion County, Florida (80% disease prevalence with 40% leaf coverage). Symptoms and signs of the disease were necrotized adaxial leaf spots only, bordered by whitish mycelia and hyphae with clamp connections, and whitish to light brown sclerotia formed in the center (<0.7 mm diameter). Symptomatic tissue was plated on acid potato dextrose agar (APDA) amended with chloramphenicol (100 mg/L) and ampicillin (30mg/L), and incubated at 20 °C for one week. Data supporting the molecular identification of this putative pathogen were gathered by PCR amplification and Sanger sequencing of the complete internal transcribed spacer (ITS) and a fragment of the large subunit (LSU) of the rRNA gene (~1.5 kb) using primers ITS1F and LR5 (FDACS-DPI PPST 2020-105211, GenBank OR492009) (White et al. 1990). The identification of the host was confirmed by Sanger sequencing of three plant barcode fragments: ITS2 (ITS2-S2F/ITS4, OR492008), ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) (rbcLa-F/rbcLa-R, GenBank OR502388), and Maturase K (matK) (matK-KIM1R/matK-KIM3F, GenBank OR502389) (Fazekas et al. 2012). MegaBLAST queries of the ITS/LSU sequence obtained here recovered a 99.61% match to the fungal pathogen Agroathelia (=Athelia) rolfsii (Sacc.) Redhead & Mullineux. (Redhead and Mullineux 2023) (Amylocorticiaceae, Agaricomycotina) strain GP3 (GenBank JABRWF010000005) (Yan et al. 2021). MegaBLAST queries of three host plant DNA barcodes recovered matches of greater than 99.62% similarity to N. nucifera sequences. After diagnosis, symptomatic dried leaf samples were deposited at Plant Industry Herbarium Gainesville (PIHG 17807) and an axenic culture was deposited at the Agricultural Research Services Culture Collection (NRRL 66964). Koch's postulates were fulfilled by the inoculation of sclerotia (as in Terrones-Salgado et al. 2022) on adaxial leaf surface of four-week- old water lily transplants obtained from an artificial pond on campus (two plants with five leaves each). One additional transplant was not inoculated and served as a control; this plant remained asymptomatic during the experimentation period. Each transplant was kept in a 27-gallon plastic container (21W × 30L × 14H in) filled with tap water containing one tablespoon of 20-20-20 all-purpose-water-soluble plant fertilizer (VPG, TX, USA) in a plant biosafety level 2 greenhouse (23 °C, >50% relative humidity, and a 12-h/12-h photoperiod). All inoculated leaves showed necrotized areas after one week and new sclerotia were observed floating on the water surface after three weeks. Fungal pathogen was reisolated and reidentified subsequently. Agroathelia rolfsii is the causal agent of southern blight, also known as grey rot, and is reported from at least in 260 plant genera, including specialty crops such as citrus, cucumber, pepper, peanuts, pumpkin, and strawberry (Farr and Rossman 2018). Agroathelia rolfsii usually causes lower stem, crown, and root rots; consequently, leaf spots are a noteworthy presentation of symptoms for this fungus.

115 Gene editing: Where are we on campus and where can it go?

Abstract Editing the genome of livestock provides solutions to otherwise intractable problems and can provide a tool to better understand the role of specific proteins during development. The potential benefit for production agriculture is so great that the USDA Agricultural Research Service has invested in 4 positions now located in a research unit at the University of Missouri with a focus currently on swine and poultry. Genome editing can result in introducing alleles from divergent populations or novel alleles to produce animals that have new proteins, modified proteins or animals that no longer produce a protein. Applications of genome editing include improving disease resistance (viral and bacterial), improving digestion, disseminating valuable genetics, improved thermoregulation, changing the body/milk composition, and creating hypoallergenic meat. Changes in these animals will improve animal welfare, animal productivity and the sustainability of animal agriculture. In addition to improving animal agriculture, gene editing has enabled a new understanding of maternal recognition of pregnancy in the pig and a better understanding of molecules involved in growth and development of pigs. With new developments in editing of just somatic cells [somatic cell gene editing (SCGE), rather than germline editing], it will be possible to edit some cells in existing animals and thus change their phenotype. SCGE technologies such as this are being developed via the biomedical community as models to lead to human clinical applications. One such application is to correct cells in the lungs that produce the CFTR protein. Correction of just 10% of the cells in the lungs is estimated to correct the lung symptoms associated with cystic fibrosis. Similar applications in production agriculture might produce animals that have novel phenotypes of an altered carcass composition or better use of nutrients. Application of genetic engineering technologies such as genome editing is limited by biology and the imagination of the investigator.

Genetic diversity, population structure, and taxonomic confirmation in annual medic (Medicago spp.) collections from Crimea, Ukraine.

Annual medic (Medicago spp.) germplasm was collected from the Crimean Peninsula of Ukraine in 2008 to fill gaps in geographic coverage in the United States department of Agriculture, Agricultural Research Service, National Plant Germplasm System (NPGS) temperate-adapted forage legume collection. A total of 102 accessions across 10 Medicago species were collected. To assess genetic diversity, population structure, and to confirm taxonomic identities, the collections were phenotypically and genetically characterized. Phenotyping included the use of 24 descriptor traits while genetic characterization was accomplished using a 3K Diversity Array Technologies (DArTag) panel developed for alfalfa (Medicago sativa L.). For both field and molecular characterizations, a reference set of 92 geographically diverse and species-representative accessions were obtained from the NPGS collection. Phenotypic descriptors showed consistency among replicated plants within accessions, some variation across accessions within species, and evident distinctions between species. Because the DArTag panel was developed for cultivated alfalfa, the transferability of markers to the species being evaluated was limited, resulting in an average of ~1,500 marker loci detected per species. From these loci, 448 markers were present in 95% of the samples. Principal component and phylogenetic analysis based on a larger set of 2,396 selected markers clustered accessions by species and predicted evolutionary relationships among species. Additionally, the markers aided in the taxonomic identity of a few accessions that were likely mislabeled. The genotyping results also showed that sampling individual plants for these mostly self-pollinating species is sufficient due to high reproducibility between single (n=3) and pooled (n=7) biological replicate leaf samples. The phenotyping and the 2,396 Single Nucleotide Polymorphism (SNP) marker set were useful in estimating population structure in the Crimean and reference accessions, highlighting novel and unique genetic diversity captured in the Crimean accessions. This research not only demonstrated the utility of the DArTag marker panel in evaluating the Crimean germplasm but also highlighted its broader application in assessing genetic resources within the Medicago genus. Furthermore, we anticipate that our findings will underscore the importance of leveraging genetic resources and advanced genotyping tools for sustainable crop improvement and biodiversity conservation in annual medic species.

Yield and yield components of some advanced Camelina (Camelina sativa L. CRANTZ) genotypes in Bolu ecological conditions

The negative effects of global warming are increasing worldwide and this increase is expected to continue. The camelina plant, which can be grown in marginal areas, stands out among other oilseed plants because it is drought-resistant and less costly. In the research, seeds belonging to 8 camelina genotypes, which were prominent in terms of oil rate, seed and oil yield, were used in the trial established in Bolu province, out of a total of 52 genotypes obtained from the seed bank of the United States Department of Agriculture, Agricultural Research Service and Germany. The study was conducted according to the Randomized Complete Block Design in Bolu Abant İzzet Baysal University, Faculty of Agriculture, Research and Application Field in the 2021-2022 production season. In the trait, each plot consisted of six rows with a row length of 3 m, a row spacing of 20 cm, and in row of 5 cm, with three replications. According to the research results; plant height 66.33-71.00 cm, number of branches 3.17-5.07 number plant-1, 1000 seed weight 1.10-1.24 g, seed yield 1095.4-1436.6 kg ha-1, oil content 36.63-40.37%, protein content 23.65-27.22%, oil yield 408.3-559.8 kg ha-1 and protein yield 279.0-391.3 kg ha-1. It was found that values between. According to the results obtained from the study, the K52 genotype in terms of seed yield, the K11 genotype in terms of oil rate and the K52 genotype in terms of protein rate came to the fore.

Budidaya Tanaman Hortikultura dan Lumbung Pangan dalam Upaya Pemanfaatan Lahan Pekarangan di Kelurahan Klitren Yogyakarta

One of the characteristics of urban areas is the increasingly limited land that can be used for plant cultivation. Only now, a lot of yard land has yet to be utilized optimally, especially for cultivating vegetables. Klitren Village, in the center of Yogyakarta City, has community-owned yard land that can be used even though the area is limited. This service activity aims to maximize the use of yard land for cultivating vegetable plants, herbal gardens, and food storage. This service activity was carried out in Klitren Village at the Asoka Farming Women's Group (FWG) in July 2022. The service activity was attended by 81 people who were a combination of women members of Asoka's FWG, the Village Head of Klitren Village, Village Agricultural Extension Officers, Lecturers, Students, Research and Community Service Units, and the Klitren Village community from various. The service is carried out through several activities, including making planting media for cultivating vegetable plants, arranging herbal gardens, and providing food barns. 100% of the evaluation results stated that the activity participants knew how to make planting media and food storage. In comparison, 66.7% said they knew how to organize and maintain an herbal garden. 66.7% of the participant's responses to the activities indicated that they were helpful and hoped they could be sustainable and improved.

1 Use of the GreenFeed bait system to assist in measuring fecal output and digesta kinetics

Abstract With increased use of automated feeders, like the bait dispenser on an automated head chamber system (AHCS; GreenFeed; C-Lock Inc., Rapid City, SD), more scientists are investigating ways to use this equipment. Scientist with the Agricultural Research Service initially conducted an experiment to determine if dosing titanium dioxide (TiO2) through an AHCS is an alternative to the traditional hand-fed dosing method for estimating fecal output (FO). The AHCS used had a 2-hopper bait dispensing system, where one hopper contained alfalfa pellets marked with 1% TiO2 and the other contained alfalfa pellets. During the morning (0800), hand-fed heifers received 32 g of TiO2-marked pellets, whereas AHCS-dosed heifers also received 32 g of marked pellets during their first visit each day. A two one-sided t-test indicated the FO estimates were similar (P = 0.04), but the AHCS dosed heifers had greater (P &amp;lt; 0.01) variability; this difference in FO variability is probably due to the increased variability in dosing time (0615 ± 6.2 h). This research has highlighted the potential for dosing cattle with a marker through the AHCS, but conventional fecal marker methods assume steady-state concentration. Our research has shown that errors associated with external marker methods are not highly associated with analytical techniques but are most influenced by dose size and sampling inaccuracy. Hence, ad libitum use of an AHCS results in non-steady-state fecal concentrations. To determine whether reliable FO estimates could be obtained under conditions of irregular but known dose times, we designed 2 experiments where the steady-state assumptions were relaxed, and fit known time measured fecal concentrations to multi-dose digesta kinetics models to estimate FO. In these experiments we used individually penned, rumen fistulated Dexter steers and limit-fed a diet of hay and protein supplement. First, after a 7-d dietary acclimation, steers were given a dose of TiO2 through the rumen fistula and again on d 14, and over 120 h after each dose, 14 spaced fecal samples were collected. In Exp. 2, steers received the first of 6 daily doses, then on d 7 no dose, and on days 8 to 12 daily dosing resumed. Beginning on d 7, when dosing was skipped, fecal sampling began and over a 120-h period 14 fecal samples were collected. For Exp. 1, marker concentration data were fit to a G2 digesta kinetics model and for Exp. 2, concentration data were fit to a multi-dose G2 digesta kinetics model assuming identical digesta kinetics for each dose and the concentration over time as the sum of each pulse. Measured FO in Exp. 2 was 11% greater than the estimates obtained from fitting measured concentrations to multi-dose digesta kinetics models.

Viroids, Satellite RNAs and Prions: Folding of Nucleic Acids and Misfolding of Proteins.

Theodor ("Ted") Otto Diener (* 28 February 1921 in Zürich, Switzerland; † 28 March 2023 in Beltsville, MD, USA) pioneered research on viroids while working at the Plant Virology Laboratory, Agricultural Research Service, USDA, in Beltsville. He coined the name viroid and defined viroids' important features like the infectivity of naked single-stranded RNA without protein-coding capacity. During scientific meetings in the 1970s and 1980s, viroids were often discussed at conferences together with other "subviral pathogens". This term includes what are now called satellite RNAs and prions. Satellite RNAs depend on a helper virus and have linear or, in the case of virusoids, circular RNA genomes. Prions, proteinaceous infectious particles, are the agents of scrapie, kuru and some other diseases. Many satellite RNAs, like viroids, are non-coding and exert their function by thermodynamically or kinetically controlled folding, while prions are solely host-encoded proteins that cause disease by misfolding, aggregation and transmission of their conformations into infectious prion isoforms. In this memorial, we will recall the work of Ted Diener on subviral pathogens.

Registration of USDA‐N6006 soybean germplasm combining high yield, flood tolerance, and elevated oil content

AbstractUSDA‐N6006 soybean [Glycine max (L.) Merr.] (Reg. no. GP‐527, PI 704140) is a conventional F4–derived early maturity group (MG) VI germplasm jointly released by USDA‐ARS and North Carolina Agricultural Research Service in 2023. USDA‐N6006 is the first MG VI, publicly released germplasm that combines flood tolerance with high‐yield lodging resistance, and elevated seed oil. Over 19 environments of the MG VI USDA Southern Uniform Soybean Trials (2017–2018), seed yield of USDA‐N6006 (3393 kg ha−1) was similar to high‐yielding lodging‐resistant check cultivars ‘NC‐Dunphy’ (3427 kg ha−1) and ‘NC‐Dilday’ (3475 kg ha−1). It matured 1 day earlier than NC‐Dunphy and exhibited similar lodging scores. Over 5 years of testing in North Carolina (2016–2019), USDA‐N6006 exhibited very robust flood tolerance. Mean flooding scores were numerically or statistically (p &lt; 0.05) superior to the four flood‐tolerant controls at both V4 and R1 growth stages. USDA‐N6006 was not intentionally bred to be flood tolerant and identified as such only through an extensive screening of “in house” USDA breeding lines. USDA‐N6006 and most of its antecedents are unique in that they are derived from unreleased breeding lines developed at the flood prone Tidewater Research station in North Carolina. Inadvertent selection for flood tolerance may have been a part of the USDA's long‐term breeding effort to improve yield. Seed oil content of USDA‐N6006 (237 g kg−1) was similar to that of elevated seed oil cultivar NC‐Dilday, but significantly higher than NC‐Dunphy (228 g kg−1) in the Uniform Trials. Seed protein content and estimated meal protein contents of USDA‐N6006 (389 g kg−1 and 46.4%, respectively) were similar to that of NC‐Dunphy. USDA‐N6006 should be excellent parental stock for applied breeding in the southern United States.

The evolution of a partnership-based breeding program for organic corn

This paper describes decades of research develop­ing a new type of corn (maize) cultivar that utilizes partnerships with seed-borne, bacterial endophytes to create environmentally friendly, nutritious corn that is better adapted to organic farming. Over time the project engaged and formed multiple, evolving networks of corn breeders and other scientists, organic farmers, nongovernmental organizations (NGOs), private companies, the U.S. Department of Agriculture Agricultural Research Service (USDA-ARS), and state agricultural univer­sities in several states. It addressed and partly resolved the need for developing (a) yield-competi­tive hybrids with greater nutrient density (methio­nine and minerals), (b) better adapted inbreds for organic production conditions, and (c) reduced pollution from nitrogen fertilizers. The partnership approach taken also differs from usual top-down mechanistic breeding approaches in that the methods of breeding entailed holistic attention, learning, and respect for what turned out to be corn plants evolving in symbiogenesis with beneficial microbial partners. Initial studies indicate that the resulting corn from the program is competitive in yield but has better nutritional value. It obtains more of its nitrogen from microbial biomass and organic matter and nitrogen fixation than does conventional corn. Its performance partially depends on seed-borne plant/microbial partnerships. This corn continues to be developed at the Mandaamin Institute but is also being commercially introduced for testing by farmers.

Boundary Integrity Testing of Containment Level 3 (Biological Safety Level 3) Laboratories.

Containment Level 3 (CL3) laboratories may require boundary integrity testing. Existing guidelines for CL3 room leakage are often subjective, lacking a definitive standard for what constitutes a "sealed" room. This study reviews global biocontainment guidelines and standards, and it compares multiple test results from global CL3 facilities by standardizing test data to an equivalent test pressure of 250 Pa. Our analysis revealed that 55% of rooms constructed using typical CL3 methodologies met the proposed testing criteria. The United States Department of Agriculture (USDA) Agricultural Research Service (ARS) greenhouse leakage rate acceptance criterion of 0.139 L/s per square meter (0.027 cfm per square foot) at a room differential pressure of 250 Pa was found to be a challenging, yet achievable standard. A two-step process is recommended for boundary integrity testing: (1) Initial leaks are identified using smoke pencil or soap bubble tests, followed by necessary repairs; (2) The room is then subjected to quantifiable leakage rate testing to verify it meets minimum requirements. In the absence of definitive local guidelines, we recommend the published ARS greenhouse leakage rate at a room differential pressure of 300 Pa of 0.152 L/s per square meter of surface area as an acceptable criterion for testing construction boundaries of CL3 laboratories built using current CL3 construction practices. For primary containment CL3 rooms, a more stringent criterion following the German Verein Deutscher Ingenieure guidelines at a room pressure differential of 250 Pa is noted as 0.03620 L/s per square meter of room surface area is more appropriate.

Registration of USDA‐N7006 soybean germplasm with increased tolerance to drought stress and 37.5% pedigree from Asian accessions PI 416937 and PI 407859‐2

AbstractUSDA‐N7006 is a conventional (non‐genetically modified) maturity group (MG) VII soybean [Glycine max (L.) Merr.] (Reg. no. GP‐525 , PI 702948) germplasm released jointly by the USDA‐ARS and the North Carolina Agricultural Research Service in January of 2023. USDA‐N7006 was released because of its drought tolerance, exotic parentage (37.5%), and high yield potential. USDA‐N7006 traces 12.5% of its parentage to PI 416937 from Japan and 25% to PI 407859‐2 from South Korea. USDA‐N7006 is the first North American soybean release derived from PI 407859‐2. USDA‐N7006 is an F4‐derived germplasm from the hybridization of USDA breeding lines TCPR01‐83 and N01‐11136. From 2015 to 2021, USDA‐N7006 was evaluated in 57 environments across the Southeast in the United Soybean Board (USB) Protein and Diversity MG VII Tests and the USDA Southern Soybean Preliminary and Uniform MG VII Tests. In the MG VII USDA and USB Protein and Diversity Tests, USDA‐N7006 yielded 96% and 98% of the check mean, respectively. Over six droughted environments in North Carolina and South Carolina, USDA‐N7006 exhibited less wilting (greater drought tolerance) than ‘USDA‐N8002’, a previously released cultivar exhibiting drought tolerance. The unique pedigree, delayed canopy wilting under drought stress, and high yield of USDA‐N7006 make it an excellent candidate for parental stock for soybean breeding programs aiming to improve drought tolerance.

Design of an Agrivoltaic System with Building Integrated Photovoltaics

Building integrated photovoltaics (BIPVs) are becoming popular as building elements such as windows, roofs, and outer walls. Because BIPVs have both a construction material function and an electricity generation function, they are a promising alternative to sustainable buildings. This study aims to propose a novel agrivoltaic system design that produces crops underneath photovoltaic (PV) modules. Regarding the fact that crop growth is significantly influenced by shading from PV modules, roof BIPVs with different shading ratios can lead to increased crop productivity. Thus, BIPV design should be investigated based on the performance estimation and feasibility evaluation of different shading ratios in an agrivoltaic system. To this end, electricity generation and crop production models are devised by polynomial regression (PR) based on field experiment data collected from the agrivoltaic system at the Agricultural Research Service Center in Naju-si, South Korea. The experiment shows that a shading ratio of 30% allows for the maximization of the profitability of electricity and soybean production in an agrivoltaic system equipped with BIPVs. As a result, this research will contribute to implementing an agrivoltaic system with various BIPVs.

An integrated agent-based simulation modeling framework for sustainable production of an Agrophotovoltaic system

The Agrophtovoltaic (APV) system is an alternative for sustainable crop production, where solar power is generated via Photovoltaic (PV) modules. Since both crop production and solar power generation activities are heavily dependent on dynamic environmental conditions, it is challenging to design an APV system based on accurate estimation of its performance. To this end, this study aims to introduce an agent-based simulation (ABS) framework integrated with polynomial regression and ridge regression. In particular, two agent types are devised, as follow: (1) The photovoltaic agent calculates electricity produced via PV modules, and estimates its profits; and (2) the crop production agent calculates crop harvests underneath the PV modules, and estimates their profits. To validate the proposed framework, field experiment data with five types of crops (i.e., corn, sesame, soybean, mung bean, and red bean) at the APV system at Jeollanam-do Agricultural Research and Extension Services in South Korea with three different shading ratios of 21.3%, 25.6%, and 32.0% have been used. In addition, for the sustainable operation of an APV system in terms of electricity generation as well as crop production, three climate change scenarios based on the shared socioeconomic pathway (SSP) are considered. The proposed framework identifies that the agrophotovoltaic system with 32% sharing ratio increases up to 20% of the total profit of normal farmland. As a result, the proposed framework enables the performance of an APV system under dynamic climate conditions to be accurately estimated, so that APV system designers can utilize it to identify a profitable long-term APV system.

Registration of high‐yielding maturity group V germplasm USDA‐N5001 with high seed and meal protein contents

AbstractUSDA‐N5001 (Reg. no. GP‐524, PI 702592) is a conventional early maturity group (MG) V soybean [Glycine max (L.) Merr.] germplasm with high yield potential and elevated seed and meal protein contents. USDA‐N5001 was jointly released as a non–genetically modified germplasm by the USDA‐ARS and the North Carolina Agricultural Research Service in January 2023. USDA‐N5001, experimental name N16‐590, was derived from the hybridization of high‐yielding breeding line N08‐145 and high‐protein breeding line Pro5‐1. Across 22 environments of the 2019 and 2020 USDA Uniform Soybean Trials Southern States, USDA‐N5001 yielded 105%, 98%, and 102% of the three checks ‘Ellis’, ‘AG55X’, and ‘TN11‐5140’, respectively. On a zero‐moisture basis, its protein content (425 g kg−1) was significantly higher (p &lt; 0.05) than those of the checks (399–402 g kg−1). The meal protein content of USDA‐N5001 (49.4%) was also significantly higher (p &lt; 0.05) than the checks (46.7%–46.9%). The new release matured 2 days and 1 day later than Ellis and AG55X, respectively, but 5 days earlier than TN11‐5140. USDA‐N5001 is the first high‐yielding, high‐seed‐ and meal‐protein MG V‐Early (relative maturity 5.3) line developed by USDA‐ARS in North Carolina. With the recent increases in production of MG V soybeans in the southeastern United States and the national focus on higher‐meal protein lines, USDA‐N5001 should be highly useful to soybean breeders and growers of conventional soybeans in the southeastern United States.

Agricultural Research Service Weed Science Research: Past, Present, and Future

AbstractThe U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed–crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America’s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency’s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being.

Agricultural management practices impact soil properties more than soil microarthropods

Soil biology is a fundamental aspect of soil quality; thus, it is imperative to understand how agricultural management impacts soil organisms. Among soil biota, microarthropods such as mites (Acari) and springtails (Collembola) act at multiple trophic levels, influencing soil microbial communities and nutrient dynamics. We investigated how agricultural management influences soil microarthropods at the U.S. Department of Agriculture (USDA) Agricultural Research Service Farming Systems Project (FSP), a long-term study comparing the sustainability and productivity of conventional and organic agriculture, in Beltsville, Maryland. We sampled soil and soil microarthropods from plots under conventional management—tilled and no till—and under organic management. Though soils managed using organic practices had significantly higher values for organic matter and several key nutrients, we found no significant differences in microarthropod abundance and QBS-ar score among agricultural systems. All agricultural plots scored lower in both metrics than undisturbed areas evaluated for comparison. Thus, differences in abiotic soil factors do not necessarily translate into differences in the biotic community; these differences may only be apparent with greater taxonomic resolution than used in this study. These results demonstrate the utility of the QBS-ar index in evaluating impacts of agricultural management on biological components of soil quality, specifically soil arthropod communities.

Fifty years of collecting wild Helianthus species for cultivated sunflower improvement

Abstract Wild Helianthus species have been undeniably beneficial in sustaining the sunflower crop by providing plant breeders with a diverse genetic pool of potentially useful traits. Exploration to collect populations of wild sunflowers is one of the more difficult and challenging activities in the conservation and utilization of these valuable genetic resources. The logistics of collecting requires careful planning, locating the target species, obtaining permission to access and collect, and timing the exploration to ensure the availability of mature seed. The US Department of Agriculture, Agricultural Research Service (USDA-ARS) established the wild Helianthus seed collection in 1976 at Bushland, Texas with the goal of collecting and conserving the broadest representative genetic diversity possible and serving as a central repository of germplasm and related information. In 1985 this collection was transferred to UDSA-ARS, North Central Regional Plant Introduction Station, Ames, Iowa. Over the last half century, 37 explorations were undertaken covering 175,000 km to collect the 53 Helianthus species from their distributional ranges in the forty-eight conterminous states in the US, three Canadian Providences (Manitoba, Saskatchewan, and Alberta), Argentina and Australia. The many explorations have created a global crop wild relatives (CWR) genebank collection. The current wild CWR sunflower genebank contains 2562 accessions of 53 species with 1065 wild Helianthus annuus accessions (42 %), 617 accessions representing populations of the 13 other wild annual species (24 %), and 880 accessions representing 39 perennial species (34 %). This collection is the largest and most genetically diverse ex situ sunflower collection in the world and is vital to the conservation of wild sunflower species for the global sunflower community.

Integration of Remote Sensing and Field Observations in Evaluating DSSAT Model for Estimating Maize and Soybean Growth and Yield in Maryland, USA

Crop models are useful for evaluating crop growth and yield at the field and regional scales, but their applications and accuracies are restricted by input data availability and quality. To overcome difficulties inherent to crop modeling, input data can be enhanced by the incorporation of remotely sensed and field observations into crop growth models. This approach has been recognized to be an important way to monitor crop growth conditions and to predict yield at the field and regional scale. In recent years, satellite remote sensing has provided high-temporal and high-spatial-resolution data that allow for generating continuous time series of biophysical parameters such as vegetation indices, leaf area index, and phenology. The objectives of this study were to use remote sensing along with field observations as inputs to the Decision Support System for Agro-Technology (DSSAT) model to estimate soybean and maize growth and yield. The study used phenology and leaf area index (LAI) data derived from Planet Fusion (daily, 3 m) satellite imagery along with field observation data on crop growth stage, LAI and yield collected at the United State Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center (BARC), Beltsville, Maryland. For maize, a total of 17 treatments (site years) were used (ten treatments for model calibration and seven treatments for validation), while for soybean (maturity groups three and four), a total of 18 treatments were used (nine for calibration and nine for validation). The calibrated model was tested against an independent, multi-location and multi-year set of phenology and yield data (2017–2020) from BARC fields. The model accurately simulated maize and soybean days to flowering and maturity and produced reasonable yield estimates for most fields and years. Model run for independent locations and years produced good results for phenology and yields for both maize and soybean, as indicated by index of agreement (d) values ranging from 0.65 to 0.93 and normalized root-mean-squared error values ranging from 1 to 20%, except for soybean maturity group four. Overall, model performances with respect to phenology and grain yield for maize and soybean were good and consistent with other DSSAT evaluation studies. The inclusion of remote sensing along with field observations in crop-growth model inputs can provide an effective approach for assessing crop conditions, even in regions lacking ground data.

A Decision Support Software Application for the Design of Agrophotovoltaic Systems in Republic of Korea

Agrophotovoltaic (APV) systems produce both solar energy and crops, so they are considered a sustainable alternative to traditional solar power plants, which can potentially destroy farmlands. However, it is challenging to diffuse APV systems because of their high installation and operating costs. Thus, to resolve the issue by maximizing the productivity and profits of an APV system, this study aims to propose a mobile-phone-based decision support system (DSS) for a supply chain network design for APV systems in South Korea using satellite imagery incorporating geographic information system (GIS) data. Particularly, polynomial regression models estimating annual corn (Zea mays) yields and the predicted generation of electricity were developed and integrated with the proposed DSS. Field experiment data provided by the APV system at Jeollanamdo Agricultural Research and Extension Services in South Korea were utilized. Two photovoltaic (PV) module types (mono-facial and bi-facial) and three different shading ratios for APV systems (21.3%, 25.6%, and 32.0%) were considered design factors for APV systems. An optimal network structure of 6 candidate APV systems and 15 agricultural markets was devised using the generalized reduced gradient (GRG) method. The profits of the six candidate APV systems are mainly affected by the transportation costs to the markets and the policy of the electricity selling prices. As a result, the proposed supply chain design framework successfully identifies an APV system network with maximum profits from crop production as well as electricity generation.